Friday, May 7, 2010

What is permanent in existence? : Thales

Thales - We do not know as much as we should like about Thales of Miletus, and what we do know is rather anecdotal in nature. He left no writings. All that is available are fragmentary references to him made by later writers who recorded memorable incidents in his career. He was a contemporary of Solon and Croesus,and the years of his life are set between 624 and 546 B.C. During a military campaign against Persia, he apparently solved the difficult logistics problem of enabling the Lydian king's army to cross the wide Halys river by digging a channel that diverted part of the flow, thereby making two narrower rivers over which bridges could be built. While traveling in Egypt, Thales worked out a way of measuring the height of the pyramids,using a simple procedure of measuring a pyramid's shadow at that time of day when one's shadow is equal to one's height. It may have been during these Egyptian travels,too, that he became acquainted with the kinds of knowledge that enabled him to predict the eclipse of the sun on May 28, 585 B.C. In a practical vein, he constructed,while in Miletus, an instrument for measuring the distance of ships sighted at sea, and as an aid to navigation, he urged sailors to use the constellation Little Bear as the surest guide for determining the direction of the north.

It was probably inevitable that anecdotes should be attached to such an extraordinary man as Thales. Plato in his Theaetetus, writes about "the jest which the clever witty Thracian handmaid is said to have made out about Thales, when he fell into a well as he was looking up at the stars. She said that he was so eager to know what was going on in heaven that he could not see what was before his feet." Plato adds that "this is a jest which is equally applicable to all philosophers," apparently unaware of another incident in Thales' life that would seem to establish a very keen awareness of what was going on around him. In his Politics, Aristotle writes that "there is...the story which is told of Thales of Miletus. It is a story about a scheme for making money, which is fathered on Thales owing his reputation for wisdom... He was reproached for his poverty, which was supposed to show the uselessness of philosophy; but observing from his knowledge of meteorology (as the story goes) that there was likely to be a heavy crop of olives [during the next summer], and having a small sum at his command, he paid down earnest-money, early in the year, for the hire of all the olive-presses in Miletus and Chios; and he managed, in the absence of any higher offer, to secure them at low rate. When the season came, and there was a sudden and simultaneous demand for a number of presses, he let out the stock he had collected at any rate he chose to fix; and making a considerable fortune, he succeeded in proving that it is easy for a philosophers to become rich if they so desire, though it is not the business which they are really about." But Thales is famous not for his general wisdom of his practical shrewdness, but because he opened up a new area of thought for which he has rightly earned the title of the first philosopher.

Thales' novel inquiry concerned the nature of things. What is everything made of or what kind of "stuff" goes into the composition of things? What Thales was trying to get at which this questions was some way of accounting for the fact that there are many different kind of things, such as earth, clouds, and oceans, and that some of these things change from time to time into something else and also that they are resemble each other in certain ways. Thales unique contribution to thought was his notion that in spites of the differences between various things there is, nevertheless, a basic similarity between them all, that the many are related to each other by the One. He assumed that some single element, some "stuff", a stuff which contained its own principle of action or change, lay at the foundation of all physical reality. To him this One, or this stuff, was water.

Although there is no record how Thales came to the conclusion that water is the cause of all things, Aristotle writes that Thales might have derived it from observation of simple events, "perhaps from seeing that nutriment of all things is moist, and that heat is generated from the moist and kept alive by it...He got his notion from this fact and from the fact that the seeds of all things have moist nature, and water is the origin of the nature of moist things." Other phenomena such as evaporation or freezing also suggest that water takes on different forms. But the accuracy of Thales' analysis of the composition of things is far less important than the fact that he raised the question concerning the nature of the world. His question had set the stage for a new kind of inquiry, one which could be debated on its merits and could either be confirmed or refuted by further analysis. In spite of his notion that "all things are full of gods,"a notion that had apparently no theological significance for him and to which he turned in an attempt to explain the power in things such as magnetic powers in stones, Thales shifted the basis of thought from a mythological base to one of scientific inquiry. And, again from his primitive starting point, others were to follow him with alternative solutions, but always his problem before them.